Archive for the 'IP Telephony' Category

The Eagle Has Landed…and so has Kapanga for Android

Monday, July 20th, 2009 by Martin Cadirola

Today is a very special day for all of us here at Kapanga.

40 years ago, one of the major events of modern era took place -landing humans on the Moon and returning them safely back home.

We thought of letting you about our recent development deserving news -kind of our own little achievement.

We have now a Kapanga Voice client running on our beloved G1 Google Phone, using the Android operating system. This time the release will be by invite-only so we’ll have a form for you to sign up very soon.

In a way, we are also thankful to NASA’s Apollo program since we wouldn’t have gone into engineering and science have we not had such an example of teamwork applied to achieving a near impossible goal. Indeed we are huge NASA fans!

All the best and thanks for the continued support!

Can anyone eavesdrop my VoIP call?

Tuesday, May 13th, 2008 by Cesar Herrero

VoIP networks use the real time protocol (RTP) to send voice over the Internet. Although RTP chunks, encodes and packetizes audio in a simple but efficient way, it has no consideration for security and data integrity.

In fact the lack of security makes RTP (and VoIP in general) a target of call “wiretapping”. How is this possible, you may ask? Well folks, read this below to try it yourself!

  1. Download and Install wireshark (
  2. Run Wireshark and start capturing packets with the appropriate NIC
  3. Place a G.711 mu law call using Kapanga
  4. On Wireshark, stop capturing packets
  5. Run statistics/RTP/Show all streams
  6. Click on the streams in the list, do a stream analysis and save the payload as an audio file
  7. Congrats: you have a recording of the call (one stream per direction)

How can we prevent this from happening? SRTP is an upgrade to RTP that provides security through encryption and authentication. Encryption specifically guarantees that the audio is unintelligible by the time it is sent out. So if we go back to item #3 on the list above we place an SRTP call instead, the recorded audio will sound like “noise”, this is because SRTP rearranges information in the payload using the AES algorithm.

So how’s your softphone’s SRTP support? As it turns out we spent quite a bit of time supporting this feature. And yes, it is available in the public site. Enjoy!

Skype down…SIP up?

Thursday, August 16th, 2007 by Martin Cadirola

This morning I learned that Skype has been down due to a “software failure” leaving millions of people unable to use it. I know lots of people use Skype for their personal and business use. I won’t be celebrating this problem even though they are an indirect competitor. What I’m interested in pointing here is that telecom carriers, operators, and service providers will use this glitch to their advantage. My question is how can we ensure that a SIP-based infrastructure can be more reliable than a peer-to-peer framework? All we know is that SIP is here to stay and service providers should be able to ensure reliability from working with far less subscribers than Skype.

For those that want to read more about the Skype glitch, you can read here and here. Oh, and here is an update.

Kapanga spricht Deutsch. Ja wohl!

Friday, April 13th, 2007 by Martin Cadirola

In our efforts to support multiple languages (we support English and Spanish), we’re happy to announce the addition of German language to both desktop and mobile versions of Kapanga Softphone. This great work has been done by our kind colleagues in Germany, the Research Group for Telecommunication Networks at the University of Applied Sciences in Frankfurt, Germany. This group works on the future of telecommunication networks with current main focuses on Quality of Service (QoS) and value added services in IP based Next Generation Networks (NGN). For further information please visit their web site.

So how can you do it? Very simple. Just follow this easy steps:

1. Click on the K icon on the upper left side of the phone

2. Select View, then Language and then Deutsch

3. Voilá, you’ve got Kapanga now working in German


PS: If you are a big fan of Kapanga and you are interested in translating it to other language, please send us an email to support at kapanga dot net and we’ll work with you on the details. Thanks!Kapanga Softphone adds German language

SIP as a foundation for building modern interactive Value Added Services (Part I)

Friday, January 5th, 2007 by Emmanuel Buu

The main purpose of my company, Interactivité Vidéo et Systèmes (IVèS), is to build and operate interactive video value added services (IVS). We deliberately chose SIP as the basis of the interactive part of our services. I would like to give here a broader discussion about what value added services are and what technologies they need.

What are Value Added Services?

Value added services (VAS) are not necessarily marketing buzz words. They are predefined business models and processes implemented on an IT or telecommunication infrastructure. eBay is a value added service, is another one, also. Newspapers with online subscription fees are also good examples. Their offerings have enough value in itself that customers are ready to pay for it.

They are opposed to what I call basic services. Those are multi-purpose tools that do not serve a business in particular, like E-mail, IM, Wikis, Blogs, telephone. They can either be offered for free or charged and they are not bound to any business process in particular.

And there is this so called Internet model that consists in setting up free services that capture a lot of audience then generate revenue streams by selling advertisement space. It allowed a surprising number of businesses and non-profit organizations to grow and have the venture capitalists interested in it. These type of companies range from the Web 2.0 kind(like You Tube, Daily Motion or NetVibes) to community services like Wikipedia. They are not easy to categorize. Some of them can potentially turn into value added services (like YouTube broadcasting content for TV companies). Some introduce innovative concepts (like location based services, tagging, social networking). Some of these are financed by wealthy investors. When such services are useful or attractive to users, they add value to the Internet as a whole, ultimately justifying the fees paid for Internet access that finance the Network evolution and deployment.

We believe at IVèS that there is a confluence of factors that will make a new wave of interactive Value Added Services emerge: The high speed Internet connectivity access is spreading, the mobile data networks are maturing, the technology is already here and oil prices are making travel more expensive.